Process of and apparatus for interconverting and adjusting the relative voltage of high-potential alternating and direct electric currents.



C. G. KOPPITZ.

A PROCESS OF AND APPARATUS FOR INTERCONVERTING AND ADJUSTING THE RELATIVE VOLTAGE OF HIGH PpTENTTAL ALTERNATING AND DIRECT ELECTRIC CURRENTS.

v APPLICATION FILED JAN- 2 1913-. 1,244,614.

Patented Oct. 30, 1917.

2 SHEETS-SHEET 1.

C. G. KOPPITZ.

PROCESS OF AND APPARATUS FOR INTERCONVERTING AND ADJUSTING THE RELATIVE VOLTAGE OF HIGH POTENTIAL ALTERNATING AND DIRECT ELECTRIC CURRENTS. I

I APPLICATION FILED JAN.2I. ISIS. v I

1,244,614. Patented 001;. 30,1017.

2 SHEETS-SHEET 2.

I 'srAr'Es PATENT ons'ron.

CARL G. KOPPITZ, 0F YOUNGSTOWN, OHIO.

230C338 0] AND APPARATUS FOR INTEBCONVEBTING AND ADJUSTING THE RELATIVE VOLTAGE OF HIGH-POTENTIAL ALTERNATING AND DIRECT ELECTRIC CURRENTB.

Specification of Letters Patent.

. Patented Oct. 30, 1917.

Application filed January 21, 1913. Serial No. 743,399.

To all whom it may concern:

Be it known that I, CARL G. Korrnz, a citizen of the United States, residing at Youngstown, in the county of Mahoning and State of Ohio, have invented certain new and useful Im rovements in Processes of and Apparatus or Interconverting and Adjusting the Relative Voltage of High- Potential Alternating and Direct Electric Currents, of which the following is a specification.

In my applications Ser. No. 646,988, filed Au st 31, 1911, now Patent No. 1,183,881 of ate May 23, 1916, and Ser. No. 724,963, filed October 10, 1912, I have described. and claimed a process of and apparatus for interconvertin'g polyphase and direct electric currents having a potential of from ten up to several hundred thousand volts, by causing the polyphase currents to traverse a closed winding and transferring unidirectional currents as arcs between segments connected to successive portions of said windings and brushes revolving in synchronism with the polyphase current. Said applications also contemplate the variation of the potential of the direct current delivered, by shifting the angular position of the brushes relative to the phases or waves of current in the windings. I

The present invention utilizes the broad principles setforth insaid prior applications, but involves the provision of two pairs of brushes of opposite polarity, which are rotated in unison but are relatively adjustable to vary the angular distance between the brushes of like polarity.

0 Referring to the accompanying draw- 1ng Figure 1 is a diagrammatic view of the electrical features of a three-phase autoconverter having a single delta-connected closed winding and two pairs of brushes;

Fig. 2 is a diagrammatic view of a similar converter having separate primary and secondary windings;

Fig. 3 is a diagrammatic view of a converter having a single winding and six brushes, in two sets;

Fig. 4 is a section of the current-collector and means for rotating and adjusting the two pairs of brushes on a plane through one pair of brushes; and

Figs. 5 and 6 are diagrammatic views of three-phase converters having a primary a sleeve surrounding the shaft. The brushes 7, 9 of one polarity are electrically connected by leads 10, 11 to a slip-ring 12 on which bears a fixed brush 13. The brushes 8, 10, respectively diametrically opposite to brushes 7, 9, are electrically connected by leads 14, 15 to a slip-ring 16 on which bears a fixed brush 17. When the concentric members carrying the brushes are adjusted to bring the two pairs of brushes into alinement,. and when the brushes are rotated in synchronism with the cycles of current, thereby maintaining predetermined positions on the traveling E. M. F. wave in the winding 1, and in apposition to the successive segments connected to those portions of the winding in which the potential wave is successively at its maximum, direct current of the highest available potential will be transmitted as arcs from the segments to the revolving brushes, and thence to the fixed brush-terminals 13, 17. By simultaneously shifting the two pairs of brushes uniform distances in opposite directions away from a diametral line coincident with the peak of the potential-wave, direct currents of correspondingly decreased potential are simultaneously collected by the two pairs of brushes, arcing from the segments thereto, and may be taken off by the brushes 13, 17, since there is a uniform difference in voltage between the successive commutator segments on each side; of the peak of the potential-wave.

The converter illustrated in Fig. 2 is identical with that shown in Fig. 1, except that it is provided with a separate primary winding 18, receiving current from the three-phase leads 2, 3, 4 and inducing current in the winding 1 which is connected to the segments. Impressed currents of moderate voltage'may thereby be stepped up to higher voltage, suflicient to cause them to are across from the segments to the brushes.

Fi 3 illustrates a converter which is identical with that shown in-Fi 1, except that it is provided with six brus es, in two sets, one set consisting of the three brushes 19, 22, 23 and the other-set'of the three brushes 20, 21, 24, 120 degrees apart, the brushes being separately carried and electrically insulated from each other by concentric revolving members. "I'he brushes-of the two sets are not necessarily diametr cally opposite, assumin this position as illustrated, only at ha f-volta e. Each brush is connected to a separate s ip-rin on which bears a fixed brush-terminal. T ese brushterminals are connected in pairs to the ends of three separate primary windings 25, which induce three-phase current for consumption in a closed winding'26. By drivingthe revolving brushes at a uniform speed asynchronous with the rotation of the currents in the winding 1, three-phase currents of any desired frequency may be collected by the revolving brushes. The relative positions of the two sets of brushes with respect to each other determines the voltage. Fig. 4 illustrates a specific means for ad- 'usting the two pairs of brushes shown 1n igs. 1 and 2. An insulating disk 80 carries the commutator segments 6. The brush 7 (not shown) and brush 8 are here carried by .a disk 27 of insulatin material, fixed on the end of a shaft '28. rushes 9 and 10, the latter not shown, are carried by an insulating disk 29 fixed on the end 0 a sleeve 30, revoluble on shaft 28. The brushes 7 and 8 on disk 27 clear the periphery of disk 29 and it is therefore apparent that disks 27 and 29 can be angularly adjusted relativel to each other within the range required. he driving-shaft 31, for example of a synchronous motor, is adjustably coupled to shaft 28 and sleeve 30 by a sleeve 32 sliding on the adjacent ends of the two shafts and sleeve. Sleeve 32 may be ad'usted by a hand lever 33 pivoted at 33 an hasthree slots 34, 35, 36. Slot 34 is longitudinal and receives a lug 37 projectin from driving-shaft 31. Slot 35 is inclin in one direction and receives 9. lug 38 rojecting from shaft 28. Slot 36 is inclined and receives a lug 39 projecting from sleeve 30. Longitudinal movement of the sleeve 32 thereby causes rotation of shaft 28 and sleeve 30 in opposite directions and through equal arcs.

The apparatus described in the abovementioned applications isefi'ective for converting alternating current into direct when volta e control is desired, but is unsatisfactory or the reverse operation, since under these conditions the time-phase relation between the voltages of the converted current and the synchronous motor drivin the brushes makes the speed-control di cult.- In the practical operation of converters as in the op osite direction illustrated in Figs. 1 and 2, satisfactory results depend upon maintaining the two cross-currents in the transformer windin The converters illustrated in Figs. 5 an 6 avoid these difliculties. In each of these modifications, a closed secondary winding 40 having three-phase terminals 3, 4, 5 is arrange in inductive relation to two parallel primary windin ing turns of which leads extend inward to the two circular sets of collector segments 43, 44. Two sets of four brushes each, rigidly spaced ninety degrees apart, are arranged to rotate in arcing proximity to the segments, one set of.brushes 45, 46, 47, 48, in Fig. 5, carried for example by a shaft, transmitting current to the segments 43, and the other set 49, 50, 51, 52, of the same fi ure, carried by a sleeve journaled on the s aft, transmitting current to segments 44; while the set of brushes 45, 47, 50, 52, in Fig. 6, is carried by the shaft and the other set 46, 48, 49, 51, by the sleeve journaled on the shaft. Brushes 46, 50, 48, 52 are electrically connected to one slip ring receiving direct cur-' rent from the negative brush-terminal, and the brushes 45, 49, 47 51 are electrically connected to the other slip ring receiving direct current from the positive brush-terminal. The impressed direct current is thereby so transmitted to the primary windings 41,

42 as to produce four revolvin magnetic poles, ninety degrees apart, in t e two primary'windings. With the revolving brushes in the position illustrated, the lines of maximum voltage are indicated by lines 5354 and 55-56.

In operating the converter of Fig. 5 to change the voltage, brushes 45, 46, 47, 48 are shifted in one direction, and brushes 49, 50, 51, 52 are simultaneously shifted in the opposite direction through an equal arc. The direct currents flowing through the two sets of brushes thereby producing substantiall sine-wave potentials in the primary win ings, one set of brushes producing a sine wave which is out of phase with the sine wave produced by the current delivered by the other set of brushes and the difference in phase is in proportion to the distance of the two sets of brushes. The two waves are compounded, the peak of the voltage remaining at its normal fixed point of commutation, so that simple three-phase alternatin current of potential dependent on the varia le distances between the two sets of brushes and on the fixed ratio of the primary and secondar windings, is delivered to the leads 3, 4, 5. he lines 57-58, 5960,

6162, 6364 indicate particular positions of the revolving brushes with reference to each other and to the lines of maximum direct current voltage. The'circular arcs and arrows indicate the corresponding directions of current flow in the windings and-the neutralizing action of the currents flowing in opposite directions in those sections of the windings subtended by two adjacent brushes of the same polarity. For instance, the section spanned by brushes 46 and 50 has currents flowing in opposite directions as shown at points 57 and-61, which, being of the same value, neutralize each other and prevent disturbances in the transformer windings.

In the converter shown in Fig. 6, the voltage change is made without reference to shifting phase-relations, by changing the distance between brushes of opposite olarity. Brushes 45, 50 and 47, 52 are shi ed in one direction from the position of maximum voltage indicated by the lines bid-54 and 5556, while brushes 48, 49 and 46, 51 are shifted in the opposite direction through an equal angle. lhus brushes 49, 50 and 51, 52, transmitting to the same segments 44, have the angles subtended by them changed in proportion to the voltage'desired. Likewise brushes 45, 48 and 46, 47, are shifted through equal arcs in the opposite direction. llhe directions of the currents flowing in the windings are indicated by the arrows on the dotted circles, the currents flowing in oppo site directions in those sections of the windings spanned by adjacent brushes, and thereby being mutually neutralized.

I claim:

1. The process of interconverting and adjusting the relative voltage of high-potential electric currents, which consists in causing alternating currents to traverse a winding, by simultaneously transmitting currents in parallel, by arcs, between successive portions of said winding and collectors, and adjusting the points of transmission equidistant from the peak of the potentialwave therein to give equal potential din erence of conversions with respect to the maximum possible difference of potential conversion.

2. The process of interconverting and adjusting the relative voltage of high-potential electric currents, which consists in causing alternating currents 'to traverse a plurality of electrically parallel windings, by simultaneously transmitting currents in parallel, by arcs, between successive portions of said windings, and collectors, and adjusting the points of transmission equidistant from the peak of the potential-wave therein to give equal potential difference oi conversions with respect to the maximum possible difference of potential conversion.

3. The process of interconverting and adjusting the relative voltage of high-potential polyphase and direct electric currents,;

which consists in causing polyphase'currents to traverse a plurality of closed electrically parallel windings, by simultaneously and synchronously transmitting currents in parallel, by arcs, between successive portions of said windings, and collectors, and adjusting the points of transmission substantially equidistant from the peak of the potential-wave therein to give equal potential difference of conversions with respect to the maximum possible difference of potential conversion.

4. The process of interconverting and adjusting the relative voltage of high potential electric currents, which consists in simultaneously transmitting currents in parallel between collectors and successive portions of a plurality of windings, thereby causing alternating currents to traverse said windings, and adjusting the points oftransmission at the collectors substantially equal distances in opposite directions from the peak of the potential wave in said windings to give equal potential difierence of conversions with respect to the maximum possible difference of potential conversion.

5. The process of adjusting the relative voltages of interconverted direct and alternating currents, which consists in simultaneously transmitting currents in parallel to successive points in a winding or windings, and varying the position of the points of transmission thereto substantially equal distances in opposite directions from the peak of the potential wave in said windings to give equal potential difi'erence of conversions with respect to the maximum possible difierence of potential conversion.

6. The process or" adjusting the'voltage of interconverted high potential director alternating currents transmitted as arcs across gaps between a series of collectors and successive portions of a winding or windings, which consists in adjusting the points of transmission at the collectors substantially equal distances in opposite directions from the peak of the potential wave in said windings to give equal potential difference of conversions with respect to the maximum possible difference of potential conversion.

7. An apparatus for interconverting and adjusting the relative voltage of electric currents, comprising a winding, an alternating-current circuit in operative relation to said winding, a group of segments, spaced leads from said winding to said segments, a plurality of sets of brushes of different polarity spaced away from said segments, means for relatively rotating said segments and brushes, and means for simultaneously shifting the brushes of like polarity angularly 'in opposite directions.

8. An apparatus for interconverting and adjustin the relative voltage of high-pm tential e ectri'c currents, comprising a winding, a polyphase-current circuit in operative relation to said winding, a grou of segme'nt-s, spaced leads from saidtwlnding to said segments, a plurality of sets of brushes of different polarity spaced away from said segments, means for relatively rotating said segments and brushes, and means for simultaneously shifting the brushes of like polarity angularly in opposite directions.

9. An apparatus for interconverting and I adjusting the relative voltage of high-potential poly hase and direct electric currents, comprising a winding, a polyphasecurrent circuit in operative relatlon to said winding, a group of segments, spaced leads from said winding to said segments, a lurality of sets of brushes of different po arity spaced away from said segments, means for relatively rotating said segments and brushes in synchronism with the currents in said winding, and means for simultaneously shifting the brushes of like polarity angularly in opposite directions.

In testimony whereof I afiix my signature in presence of twowitnesses.

CARL G. KOPPITZ.

Witnesses:

J. W. BLACKBURN, B. M. GEE. 

